// Author:  cirakg & claude ai
// Summary: The Manage entry form (README 10.2): one action on an entry by its ID, applied now or queued for the PIN (README 7.9).
//
// Three parts:
//   * ManageAction: one parsed request, and its byte form for the queue.
//   * ManageForm.read(): the mg* fields to a ManageAction or a problem.
//   * ManageRun: a job that checks the action against the entry and then
//     applies it, or queues it (ChangeQueue) when it touches a locked
//     entry: edit, replace, counter, "Don't require PIN", the favourite
//     mark and delete wait until the PIN is entered on the watch. "Require PIN" waits too while
//     the watch is locked (it needs the master key), but is applied at the
//     next PIN without confirming (ChangeQueue.applyLocks). Moving never waits:
//     the order isn't protected and a position is absolute, so applying a
//     move twice can't hit another entry.
// Replacing a code's contents runs CodeCheck with the entry's own options
// (a sub-job, so a large 2D code can't trip the watchdog). For a locked
// entry the options are encrypted, so that check runs when the PIN confirms;
// everything else about a REPLACE (Base32, the contents' size) is checked
// before it is queued. With 4 KB of contents every byte loop (UTF-8 check,
// opening and re-sealing the record, wiping) gets a step of its own, and
// the wipes at the end run in pieces (Jobs.Wiper).

import Toybox.Lang;

class ManageAction {

    // mgAction list values (resources/settings/settings.xml). Stored in the
    // queue: never renumber.
    static const EDIT = 0;
    static const MOVE = 1;
    static const LOCK = 2;
    static const UNLOCK = 3;
    static const REPLACE = 4;
    static const COUNTER = 5;
    static const DELETE = 6;
    static const FAVORITE = 7;
    static const UNFAVORITE = 8;

    static const NAMES = ["Edit details", "Move", "Require PIN", "Don't require PIN", "Replace contents", "Set counter", "Delete",
        "Mark as favourite", "Remove favourite"];

    // Codec tags of the queued form.
    static const T_ID = 1;
    static const T_ACTION = 2;
    static const T_NAME = 3;
    static const T_ACCOUNT = 4;
    static const T_GROUP = 5;
    static const T_POSITION = 6;
    static const T_MATERIAL = 7;
    static const T_COUNTER = 8;
    static const T_LABEL = 9;
    static const T_DECODED = 10;
    static const T_REF = 11;

    // In "Edit details", this value clears a field; empty keeps it.
    static const CLEAR = "-";

    var id as String = "";
    var action as Number = EDIT;
    var name as String = "";
    var account as String = "";
    var group as String = "";
    var position as Number = 0;
    // REPLACE: the decoded OTP secret or the new code contents, once
    // checked against the entry (a 0.9.0 queue item may hold the raw text
    // of a code's contents instead). Wiped after use. Queued, it is a
    // storage value of its own (ChangeQueue, `ref`).
    var material as ByteArray? = null;
    // REPLACE from the form: the raw field text until ManageRun checks it.
    // Never queued.
    var text as String? = null;
    // A queued REPLACE: the number of its material record, -1 for none.
    var ref as Number = -1;
    var counter as Long = 0l;
    // True once `material` holds the checked secret (decoded from Base32)
    // or contents (CodeForm.contents), not raw text.
    var decoded as Boolean = false;
    // "Bank (carol)", kept so the queue can be shown while locked.
    var label as String = "";

    function initialize() {
    }

    // "Delete K7F2 Bank (carol)".
    function describe() as String {
        var verb = NAMES[action] as String;
        var target = label.length() > 0 ? id + " " + label : id;
        if (action == MOVE) {
            return "Move " + target + " to position " + position;
        }
        if (action == COUNTER) {
            return "Set the counter of " + target + " to " + counter;
        }
        return verb + ": " + target;
    }

    function wipe() as Void {
        Bytes.wipe(material);
        material = null;
        text = null;
    }

    function toBytes() as ByteArray {
        var w = new Codec.Writer();
        w.addText(T_ID, id);
        w.addInt(T_ACTION, action);
        w.addText(T_NAME, name);
        w.addText(T_ACCOUNT, account);
        w.addText(T_GROUP, group);
        w.addInt(T_POSITION, position);
        var m = material;
        if (m != null) {
            w.addBytes(T_MATERIAL, m);
        }
        w.addInt(T_COUNTER, counter);
        w.addText(T_LABEL, label);
        w.addBool(T_DECODED, decoded);
        if (ref >= 0) {
            w.addInt(T_REF, ref);
        }
        return w.bytes;
    }

    // The action, or null when the bytes are malformed.
    static function fromBytes(data as ByteArray) as ManageAction? {
        var map = Codec.decode(data);
        if (map == null) {
            return null;
        }
        var a = new ManageAction();
        var id = map[T_ID];
        var action = map[T_ACTION];
        var position = map[T_POSITION];
        var counter = map[T_COUNTER];
        if (!(id instanceof String) || !(action instanceof Long) || !(position instanceof Long) || !(counter instanceof Long)) {
            return null;
        }
        if (action < EDIT || action > UNFAVORITE || !Entry.isValidId(id)) {
            return null;
        }
        a.id = id;
        a.action = action.toNumber();
        a.position = position.toNumber();
        a.counter = counter;
        a.name = textOf(map[T_NAME]);
        a.account = textOf(map[T_ACCOUNT]);
        a.group = textOf(map[T_GROUP]);
        a.label = textOf(map[T_LABEL]);
        var m = map[T_MATERIAL];
        a.material = m instanceof ByteArray ? m : null;
        var decoded = map[T_DECODED];
        a.decoded = decoded instanceof Boolean && decoded;
        var ref = map[T_REF];
        a.ref = ref instanceof Long && ref >= 0 && ref < 0x10000 ? ref.toNumber() : -1;
        return a;
    }

    static function textOf(value as ByteArray or String or Long or Boolean or Null) as String {
        return value instanceof String ? value : "";
    }
}

module ManageForm {

    const SWITCH = "mgApply";
    const STATUS = "mgStatus";
    const SECRET = "mgSecret";

    const FIELDS = ["mgId", "mgAction", "mgName", "mgAccount", "mgGroup", "mgPosition", "mgSecret", "mgCounter"];

    function defaults() as Dictionary<String, String or Number or Long> {
        return {
            SECRET => "",
            "mgId" => "",
            "mgAction" => ManageAction.EDIT,
            "mgName" => "",
            "mgAccount" => "",
            "mgGroup" => "",
            "mgPosition" => 1,
            "mgCounter" => 0l
        } as Dictionary<String, String or Number or Long>;
    }

    // The requested action (not yet checked against the entry), or the
    // problem. The form content goes into `content` for the form hash.
    function read(store as Forms.Store, content as Forms.Content) as ManageAction or String {
        for (var i = 0; i < FIELDS.size(); i++) {
            content.add(store.get(FIELDS[i] as String));
        }
        var a = new ManageAction();
        a.id = Forms.text(store, "mgId").toUpper();
        if (a.id.length() == 0) {
            return "Entry ID: missing. The IDs are under Entry IDs in the watch menu";
        }
        if (!Entry.isValidId(a.id)) {
            return "Entry ID: '" + Text.clip(a.id, 8) + "' is not an ID. IDs have 4 characters, like K7F2";
        }
        var action = Forms.number(store, "mgAction");
        if (action == null || action < ManageAction.EDIT || action > ManageAction.UNFAVORITE) {
            return "Action: choose one from the list";
        }
        a.action = action;
        if (action == ManageAction.EDIT) {
            a.name = Forms.text(store, "mgName");
            a.account = Forms.text(store, "mgAccount");
            a.group = Forms.text(store, "mgGroup");
            if (a.name.length() == 0 && a.account.length() == 0 && a.group.length() == 0) {
                return "Edit details: fill in a new name, account or group ('-' clears one)";
            }
            var problem = Forms.checkName("Name", a.name, Entry.MAX_NAME_BYTES);
            if (problem == null) {
                problem = Forms.checkName("Account", a.account, Entry.MAX_NAME_BYTES);
            }
            if (problem == null) {
                problem = Forms.checkName("Group", a.group, Entry.MAX_GROUP_BYTES);
            }
            return problem != null ? problem : a;
        }
        if (action == ManageAction.MOVE) {
            var position = Forms.number(store, "mgPosition");
            if (position == null || position < 1) {
                return "Position: 1 or more";
            }
            a.position = position;
        } else if (action == ManageAction.REPLACE) {
            var secret = Forms.rawText(store, SECRET);
            if (secret.length() == 0) {
                return "Replace: enter the new secret or contents"; // only spaces: ManageRun says so, in steps
            }
            a.text = secret; // checked against the entry by ManageRun
        } else if (action == ManageAction.COUNTER) {
            var counter = Forms.long(store, "mgCounter");
            if (counter == null || counter < 0) {
                return "Counter: a whole number, 0 or more";
            }
            a.counter = counter;
        }
        return a;
    }

    function reset(store as Forms.Store, everything as Boolean) as Void {
        store.set(SECRET, "");
        if (everything) {
            var d = defaults();
            var keys = d.keys();
            for (var i = 0; i < keys.size(); i++) {
                store.set(keys[i], d[keys[i]] as String or Number or Long);
            }
        }
        store.set(SWITCH, false);
    }
}

// Checks one action against its entry and applies or queues it. When step()
// returns true, `message` says what happened; `failed` is true when nothing
// changed because of a problem, `queued` when it waits for the PIN.
class ManageRun extends Jobs.Job {

    var message as String = "";
    var failed as Boolean = false;
    var queued as Boolean = false;
    // Remarks (a check digit added, too large for the screen).
    var notes as Array<String> = [] as Array<String>;

    private var _vault as Vault;
    private var _a as ManageAction;
    private var _confirmed as Boolean;
    private var _header as Entry? = null;
    private var _check as CodeCheck? = null;
    private var _cache as ByteArray? = null;
    // Buffers to wipe once the run ends; large ones take steps of their own.
    private var _wiper as Jobs.Wiper = new Jobs.Wiper();
    private var _wiping as Boolean = false;
    // A code REPLACE: CodeCheck is still to start, with this payload text
    // (null: from the queue, still to be read from `material`).
    private var _needsCheck as Boolean = false;
    private var _payload as String? = null;
    // How far queued contents are checked as UTF-8.
    private var _utf8At as Number = 0;
    // A REPLACE's raw text, prepared in steps before it is checked
    // (prepareText): a 0.9.0 item's raw bytes checked as UTF-8, then the
    // spaces around it found, in pieces (kilobytes of either are a byte or
    // character loop).
    private var _rawAt as Number = 0;
    private var _chars as Array<Char>? = null;
    private var _trimStart as Number = 0;
    private var _trimEnd as Number = -1;
    private var _trimmed as String? = null;
    // A REPLACE: the entry opened in the step before it is re-sealed.
    private var _entry as Entry? = null;

    // Raw OTP secrets longer than this are refused before Base32.decode's
    // character loop (128 bytes are 205 Base32 characters; this leaves room
    // for spaces).
    static const MAX_SECRET_TEXT = 1024;
    // Contents checked as UTF-8 per step (up to 30 bytecodes a byte).
    static const UTF8_STEP_BYTES = 1024;
    // Characters looked at per step when trimming the raw text.
    static const TRIM_STEP_CHARS = 512;

    // confirmed: the PIN was just entered for this action (from the queue),
    // so it is applied, never queued again.
    function initialize(vault as Vault, action as ManageAction, confirmed as Boolean) {
        Job.initialize();
        _vault = vault;
        _a = action;
        _confirmed = confirmed;
    }

    function step(budget as Number) as Boolean {
        if (_wiping) {
            return _wiper.step(Jobs.Wiper.STEP_BYTES);
        }
        var check = _check;
        if (check != null) {
            if (!check.step(budget)) {
                return false;
            }
            _check = null;
            var err = check.error;
            if (err != null) {
                return fail(err);
            }
            notes.addAll(check.notes);
            // Applying gets the next step: packing a large matrix used
            // much of this event's budget.
            _cache = check.cache;
            return false;
        }
        if (_header == null) {
            if (_a.action == ManageAction.REPLACE && !_a.decoded && _trimmed == null) {
                return prepareText();
            }
            try {
                return resolve();
            } catch (e instanceof VaultError) {
                return fail(problemText(e));
            }
        }
        if (_needsCheck) {
            try {
                return prepareCheck();
            } catch (e instanceof VaultError) {
                return fail(problemText(e));
            }
        }
        return finish(_cache);
    }

    // Find the entry and check the action against it. Returns true when
    // the run ends here (a problem); false to continue with the next step.
    private function resolve() as Boolean {
        var a = _a;
        if (_vault.pendingIds().indexOf(a.id) >= 0) {
            return fail(a.id + " waits for your PIN on the watch. Enter the PIN there first");
        }
        if (_vault.ids().indexOf(a.id) < 0) {
            return fail("No entry " + a.id + ". The IDs are under Entry IDs in the watch menu");
        }
        var header = _vault.header(a.id);
        if (header == null) {
            if (a.action == ManageAction.DELETE) {
                _vault.remove(a.id); // a damaged entry can always be deleted
                message = "Deleted damaged entry " + a.id;
                return true;
            }
            return fail(a.id + " is damaged. Delete it and add it again");
        }
        _header = header;
        if (a.label.length() == 0) {
            a.label = Forms.label(header.name, header.account);
        }
        var problem = checkAgainst(header);
        if (problem != null) {
            return fail(problem);
        }
        if (mustWait(header)) {
            return queue();
        }
        if (a.action == ManageAction.REPLACE && header.kind == Entry.KIND_CODE) {
            _needsCheck = true; // CodeCheck with the entry's options (prepareCheck)
            return false;
        }
        return false;
    }

    // Problems that don't depend on the PIN.
    private function checkAgainst(header as Entry) as String? {
        var a = _a;
        var isOtp = header.kind == Entry.KIND_OTP;
        if (a.action == ManageAction.COUNTER && !(isOtp && header.type == Entry.OTP_HOTP)) {
            return "Set counter: " + a.id + " is not a HOTP entry";
        }
        if (a.action == ManageAction.EDIT && !isOtp && a.account.length() > 0) {
            return "Account: " + a.id + " is a barcode, which has no account";
        }
        if (a.action == ManageAction.LOCK && header.locked) {
            return a.id + " already requires the PIN";
        }
        if (a.action == ManageAction.UNLOCK && !header.locked) {
            return a.id + " doesn't require the PIN";
        }
        if (a.action == ManageAction.FAVORITE && header.favorite) {
            return a.id + " is already a favourite";
        }
        if (a.action == ManageAction.UNFAVORITE && !header.favorite) {
            return a.id + " is not a favourite";
        }
        if (a.action == ManageAction.REPLACE && !a.decoded) {
            // Checked before queueing, so a locked entry's queue item holds
            // only the decoded secret or the checked contents.
            var text = a.text as String;
            var trimmed = _trimmed as String;
            a.text = null;
            if (!isOtp) {
                var contents = CodeForm.contentsOf(text, trimmed, header.type);
                if (contents instanceof String) {
                    return contents;
                }
                a.material = contents;
                a.decoded = true;
                _payload = Codes.isLinear(header.type) ? trimmed : text;
                return null;
            }
            if (text.length() > MAX_SECRET_TEXT) {
                return "Secret: too long";
            }
            var decoded = OtpForm.decodeSecret(trimmed); // trimmed: no character loop there
            if (decoded instanceof String) {
                return decoded;
            }
            a.material = decoded;
            a.decoded = true;
            if (decoded.size() < OtpForm.WEAK_SECRET_BYTES) {
                notes.add("Warning: the secret is only " + decoded.size() * 8 + " bits (80 or more recommended)");
            }
        }
        return null;
    }

    // Locked entries' sensitive actions wait for the PIN (README 7.9).
    private function mustWait(header as Entry) as Boolean {
        if (_confirmed) {
            return false;
        }
        var action = _a.action;
        if (action == ManageAction.MOVE) {
            return false;
        }
        if (action == ManageAction.LOCK) {
            return !_vault.session.isUnlocked();
        }
        return header.locked;
    }

    private function queue() as Boolean {
        try {
            ChangeQueue.addWith(_vault, _a, _wiper);
        } catch (e instanceof VaultError) {
            return fail(e.code == VaultError.LIMIT ? e.getErrorMessage() as String : "storage full");
        }
        queued = true;
        message = (_a.action == ManageAction.LOCK ? "Locks when you next enter your PIN on the watch: "
            : "Waiting for your PIN on the watch: ") + _a.describe();
        wipeAction();
        return ending();
    }

    // One step of preparing a REPLACE's raw text: a 0.9.0 item's raw bytes
    // become text (checked as UTF-8 in pieces); text longer than any valid
    // input is refused; then the spaces around it are found in pieces.
    private function prepareText() as Boolean {
        var a = _a;
        var text = a.text;
        if (text == null) {
            var raw = a.material;
            if (raw == null) {
                return fail("Replace: enter the new secret or contents");
            }
            if (_rawAt < raw.size()) {
                var end = _rawAt + UTF8_STEP_BYTES < raw.size() ? _rawAt + UTF8_STEP_BYTES : raw.size();
                _rawAt = Bytes.utf8Prefix(raw, _rawAt, end);
                return _rawAt < 0 ? fail("Replace: the new secret or contents are damaged") : false;
            }
            a.text = Bytes.toUtf8Checked(raw);
            a.material = null;
            _wiper.add(raw);
            return false;
        }
        var chars = _chars;
        if (chars == null) {
            if (text.length() > Entry.MAX_PAYLOAD_BYTES) {
                return fail("Replace: too long (" + text.length() + " characters, at most " + Entry.MAX_PAYLOAD_BYTES + ")");
            }
            chars = text.toCharArray();
            _chars = chars;
            _trimEnd = chars.size();
            return false;
        }
        var budget = TRIM_STEP_CHARS;
        while (budget > 0 && _trimStart < _trimEnd && Text.isSpace(chars[_trimStart])) {
            _trimStart++;
            budget--;
        }
        if (budget == 0) {
            return false;
        }
        while (budget > 0 && _trimEnd > _trimStart && Text.isSpace(chars[_trimEnd - 1])) {
            _trimEnd--;
            budget--;
        }
        if (budget == 0) {
            return false;
        }
        _trimmed = text.substring(_trimStart, _trimEnd);
        _chars = null;
        return false;
    }

    // One step towards CodeCheck: queued contents are read as text first
    // (the UTF-8 check is a byte loop, done in pieces), then the entry is opened for its
    // options.
    private function prepareCheck() as Boolean {
        var a = _a;
        var payload = _payload;
        if (payload == null) {
            var m = a.material as ByteArray;
            if (_utf8At < m.size()) {
                var end = _utf8At + UTF8_STEP_BYTES < m.size() ? _utf8At + UTF8_STEP_BYTES : m.size();
                _utf8At = Bytes.utf8Prefix(m, _utf8At, end);
                return _utf8At < 0 ? fail("the new contents are damaged") : false;
            }
            _payload = Bytes.toUtf8Checked(m);
            return false;
        }
        var entry = _vault.openWith(a.id, _wiper);
        var options = entry.options;
        wipeLater(entry);
        _needsCheck = false;
        _payload = null;
        _check = new CodeCheck((_header as Entry).type, payload, options);
        return false;
    }

    // Apply the action; cache: a checked code's packed matrix, or null.
    private function finish(cache as ByteArray?) as Boolean {
        var a = _a;
        if (a.action == ManageAction.REPLACE && _entry == null) {
            // Opening and re-sealing a large code are a step each.
            try {
                _entry = _vault.openWith(a.id, _wiper);
            } catch (e instanceof VaultError) {
                return fail(problemText(e));
            }
            return false;
        }
        var target = a.id + (a.label.length() > 0 ? " " + a.label : "");
        try {
            if (a.action == ManageAction.MOVE) {
                _vault.move(a.id, a.position - 1);
                message = "Moved " + target + " to position " + (_vault.ids().indexOf(a.id) + 1);
            } else if (a.action == ManageAction.COUNTER) {
                _vault.setCounter(a.id, a.counter);
                message = "Set the counter of " + target + " to " + a.counter;
            } else if (a.action == ManageAction.DELETE) {
                _vault.remove(a.id);
                message = "Deleted " + target;
            } else {
                var problem = changeEntry();
                if (problem != null) {
                    return fail(problem);
                }
                if (cache != null) {
                    _vault.saveCodeCacheWith(a.id, cache, _wiper);
                }
            }
        } catch (e instanceof VaultError) {
            return fail(problemText(e));
        }
        wipeAction();
        return ending();
    }

    // Edit, lock, unlock, (un)favourite or replace: open, change, re-seal.
    // Null or the problem.
    private function changeEntry() as String? {
        var a = _a;
        var target = a.id + (a.label.length() > 0 ? " " + a.label : "");
        var opened = _entry;
        _entry = null;
        var entry = opened != null ? opened : _vault.openWith(a.id, _wiper);
        if (a.action == ManageAction.EDIT) {
            entry.name = edited(entry.name, a.name);
            entry.account = edited(entry.account, a.account);
            entry.group = edited(entry.group, a.group);
            if (entry.name.length() == 0 && (entry.kind == Entry.KIND_CODE || entry.account.length() == 0)) {
                wipeLater(entry);
                return entry.kind == Entry.KIND_CODE ? "Name: a barcode needs a name" : "An OTP entry needs an issuer or an account";
            }
            message = "Edited " + a.id + ": " + Forms.label(entry.name, entry.account)
                + (entry.group.length() > 0 ? ", group " + entry.group : "");
        } else if (a.action == ManageAction.LOCK || a.action == ManageAction.UNLOCK) {
            entry.locked = a.action == ManageAction.LOCK;
            message = target + (entry.locked ? " now requires the PIN" : " no longer requires the PIN");
        } else if (a.action == ManageAction.FAVORITE || a.action == ManageAction.UNFAVORITE) {
            entry.favorite = a.action == ManageAction.FAVORITE;
            message = target + (entry.favorite ? " is now a favourite" : " is no longer a favourite");
        } else {
            var material = a.material as ByteArray;
            if (entry.kind == Entry.KIND_OTP) {
                _wiper.add(entry.secret);
                entry.secret = Bytes.copy(material);
                message = "Replaced the secret of " + target;
            } else {
                _wiper.add(entry.payload);
                entry.payload = Bytes.copy(material);
                message = "Replaced the contents of " + target;
            }
        }
        try {
            _vault.updateWith(entry, _wiper);
        } catch (e instanceof VaultError) {
            wipeLater(entry);
            throw e;
        }
        wipeLater(entry);
        return null;
    }

    // Blank keeps the old value, "-" clears it, anything else replaces it.
    private function edited(old as String, requested as String) as String {
        if (requested.length() == 0) {
            return old;
        }
        return requested.equals(ManageAction.CLEAR) ? "" : requested;
    }

    private function fail(problem as String) as Boolean {
        failed = true;
        message = problem;
        var entry = _entry;
        if (entry != null) {
            wipeLater(entry);
            _entry = null;
        }
        wipeAction();
        return ending();
    }

    // The action's material goes to the wiper.
    private function wipeAction() as Void {
        _wiper.add(_a.material);
        _a.material = null;
        _a.text = null;
    }

    private function wipeLater(entry as Entry) as Void {
        _wiper.add(entry.secret);
        _wiper.add(entry.payload);
        entry.secret = null;
        entry.payload = null;
    }

    // The run is over once its buffers are wiped: small ones now, large
    // ones in the next steps.
    private function ending() as Boolean {
        if (_wiper.left() <= Jobs.Wiper.INLINE_BYTES) {
            _wiper.step(Jobs.Wiper.INLINE_BYTES);
            return true;
        }
        _wiping = true;
        return false;
    }

    static function problemText(e as VaultError) as String {
        if (e.code == VaultError.LOCKED) {
            return "the watch is locked; try again after entering the PIN";
        }
        if (e.code == VaultError.FULL) {
            return "storage full";
        }
        if (e.code == VaultError.NOT_FOUND) {
            return "the entry no longer exists";
        }
        if (e.code == VaultError.DAMAGED) {
            return "the entry is damaged";
        }
        var m = e.getErrorMessage();
        return m != null ? m : "not possible";
    }
}